1. Field of the Invention
The present invention relates to an automatic working apparatus incorporating a play-back control function and a method of controlling the automatic working apparatus.
2. Description of the Prior Art
A control in which coordinates of bend points in a path or route to be followed or traced by an object which is controlled in respect of the moving path or route thereof and herein referred to as the route-controlled object are stored in a memory device and read out sequentially thereby to guide the route-controlled object along a substantially straight line segment has been known and referred to as the point-to-point control (or P.T.P. control in an abridgement). In this connection, the route-controlled object is a part of an automatic working apparatus and is usually constituted by a portion adapted to perform a treatment on a work or a portion positioned near the working portion. Further, the term "work" is intended to mean an article or thing destined to be worked, machined, transported or subjected to similar treatment or processing by the automatic working apparatus. For example, in the case in which the automatic working apparatus is a painting machine, then the work is a subject to be applied with a paint material.
In the automatic working apparatus, a high positional accuracy of the route along which the route-controlled object is displaced as well as a high speed at which the route-controlled object is moved are required. When the route-controlled object is moved from a bend point at which the moving direction is changed to a next bend point, the route-controlled object is progressively accelerated starting from the first mentioned bend point and decelerated progressively as the route-controlled object approaches to the next bend point. The commands for changing the moving speed of the route-controlled object are conventionally issued on the basis of operator's judgement. Consequently, the teaching procedures become necessarily troublesome and there may be produced erroneous speed commands.